|Quadrangle map, 1:250,000-scale||NB|
|Quadrangle map, 1:63,360-scale||A-2|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This prospect is at an elevation of about 4,700 feet on the north valley wall of lower Chathenda Creek. It is 3,000 feet northwest of Bonanza and 3,500 feet southeast of the summit of hill 5940. The site is in the NW1/4 of section 35, T. 4 N., R. 19 E., of the Copper River Meridian. This is locality 40 of Richter and others (1975) and may be included in National Park Service locality WRST-60 or WRST-61 (unpublished data). Cobb and Richter (1980) included this prospect under the name 'Chathenda Cr.'. It is located to within a few hundred feet.|
Geologic descriptionAt this prospect, gold-bearing quartz-pyrite veins locally cut iron-oxide-stained altered zones in volcanic breccia of the Cretaceous, Chisana Formation (Richter and Matson, 1970 [OFR 70-275]; Richter and Jones, 1973; Richter and others, 1975). The volcanic rocks are intruded by the mid-Cretaceous, Chisana pluton about 4,000 feet northwest of the prospect. The Chisana pluton varies from clinopyroxene diorite to monzonite and has a K/Ar date of 110 +/- 3.0 Ma (Richter, Lanphere, and Matson, 1975).
|Geologic map unit||(-141.895429107713, 62.0815360317364)|
|Mineral deposit model||Polymetallic veins (Cox and Singer, 1986; model 22c)|
|Mineral deposit model number||22c|
|Age of mineralization||Mid-Cretaceous? The deposit may be related to emplacement of the Chisana pluton which has a K/Ar date of 110 +/- 3.0 Ma (Richter, Lanphere, and Matson, 1975).|
|Alteration of deposit||Pyrite and quartz veining and replacement(?). Oxidation has produced abundant iron-staining.|
|Workings or exploration||A number of small gold-bearing quartz-pyrite lodes occur in mineralized volcanic country rock of the Cretaceous, Chisana Formation on the north side of Chathenda Creek (also see NB080 and NB092). By 1940 a large group of claims had been staked in this area but exploration, including trenches and some short adits, was unsuccessful.|
|Indication of production||None|
Additional commentsThe prospect is in the Wrangell-St. Elias National Preserve.
Cobb, E.H., and Richter, D.H., 1980, Summaries of data on and list of references to metallic and selected nonmetallic mineral deposits in the Nabesna quadrangle, Alaska: U.S. Geological Survey Open-File Report 80-927, 117 p.
Richter, D.H., and Jones, D.L., 1973, Reconnaissance geologic map of the Nabesna A-2 quadrangle, Alaska: U.S. Geological Survey Miscellaneous Investigations Series Map I-749, 1 sheet, scale 1:63,360.
Richter, D.H., and Matson, N.A., Jr., 1970, Geochemical data from the Nabesna A-2 quadrangle, Alaska: U.S. Geological Survey Open-File Report 70-275, 12 p., 1 sheet, scale 1:63,360.
Richter, D.H., Lanphere, M.A., and Matson, N.A., Jr., 1975, Granite plutonism and metamorphism, eeastern Alaska Range, Alaska: Geological Society of American Bulletin, v. 86, p. 819-820.
|Reporters||Travis L. Hudson (Applied Geology)|
|Last report date||11/24/2002|